1. Field of the Invention
The present invention relates to a winding machine for producing at least one wound roll from a supplied material web, such as a paper or endless cardboard web, in which the material web or the web sections generated therefrom are each wound on a core formed by a tube or the like. The invention further includes a continuous loop encircling at least one winding roller and a tensioning device with at least one winding gap that regulates the winding tightness of the wound roll of material web.
2. Discussion of Background Information
The winding rollers used in the paper industry are in most cases manufactured from steel or gray cast iron. The so-called functional surface of this type of winding roller, i.e., where the roller sleeve contacts the wound roll, is generally covered with a hard coating. Current developments in paper manufacturing are now increasingly tending toward more sensitive paper, higher web speeds, and larger winding diameters. This can cause, amongst other things, air problems, such as the formation of bubbles, winding defects, too high a tension level that is nip-induced, and layer shifts. In order to counter these problems, winding rollers are more and more frequently covered with soft coatings. This type of winding roller is typically composed of a basic metal body and a coating that has either been vulcanized or glued onto it. However, a disadvantage of such winding rollers is that, amongst other things, the soft coatings have a relatively short service life. Furthermore, soft roller coatings are expensive and applying them is very time-consuming. For example, the residue of the old coating must be removed initially and appropriate preparations must be undertaken before the new coating can ultimately be applied. Apart from these disadvantages resulting from the requirement for a coating, the time needed to change a respective roller is normally also very great. Thus, at least one spare roller having the same coating must be made available.
As used herein, the term "soft" is meant to encompass a range of softness as described in Pussy & Jones (P&J). If expressed in terms of ranges, what is meant by the term soft is the range from about 80 P&J to about 105 P&J, more preferably from about 85 P&J to about 100 P&J, and most preferably from about 90 P&J to about 95 P&J. If, on the other hand, the term soft is expressed in terms of upper and lower values, the upper values are about 105 P&J, and they are preferably less than 105 P&J, more preferably less than 100 P&J, and most preferably less than 95 P&J. On the lower side, the lower values are about 80 P&J, and they are preferably greater than 80 P&J, more preferably greater than 85 P&J, and most preferably greater than 90 P&J.
In a paper machine known from DE-PS 51 988, the paper web is fed, amongst other things, through a roller press across whose upper press roller a continuous rubber blanket is fed. Another press roller is described in DE 35 01 635 A1, which incorporates a flexible press sleeve that is impervious to fluid, through which a supporting body that is positioned in a fixed or rotatable manner extends.
Nonetheless, these known rollers are not used to wind up a supplied material web or to re-roll an already finished wound roll.